The Nugget Design Of Aluminum Alloy Spot Welding

The aluminum alloys are widespread used in the machinery, the transportation, astronautics and the war industry and so on because of the light weight, the ample resources, overall good performance. The aluminum alloys resistance spot welding is most important welding technique in the automobile body automatic metaphase mid-production. But in the aluminum alloys resistance spot welding there is a problem that Spot intensity is bad and the use efficiency is low. Therefore research of the aluminum alloys spot welding fusion is very important.The resistance spot welding is one of broadest welding methods. The related spot forms the theory and the spot welding quality control technology research throughout the domain the main hotspot. Through the research of aluminum alloys spot welding fusion breeding process, I discovered that control one of its organization and performance keys is to obtain the tiny even isometric crystal. The crystal grain is the near future on international to the traditional material promotion and one of creation new alloys underbid craft methods. Therefore, to utilize the different crystal grain thin method to obtain the tiny isometric crystal, namely crystallization organization's tiny processing.The intermediate alloys to the aluminum alloys outstanding thin effect enables it to obtain the widespread use in the industrial production. But because the intermediate alloys preparation process or joins the way differently, causes it to contain the shape and the distribution different, then has the different thin effect to the aluminum alloys, these intermediate alloys preparation crafts complex, the cost is high.Considered from the aluminum alloys work piece surface that, spreads in the aluminum alloys surface spreads material and so on Ti, B2O3, Cr, Zr, Mn, forms the aluminum melt nucleus intermediate alloys crystal grain thin medicinal preparation, has the massive effective nitrogen shape nuclear core, enhances the crystal the shape nucleus rate, thus thin crystal grain. Experiments show that adding coating materials increased regional axis crystal grain refinement, solder joint strength can be increased by 2 / 3.The analysis of Ti, B2O3, Zr, Cr, Mn shows that having a core of the heterogeneity, nuclei were wetting angle with very small form the nucleus "basal",equiaxed nuclei proliferation, diffusing the formation of precipitates caused the increased resistance movement, increase the plasticity of the spot. So that the solder joint shear rafah has been markedly enhanced ability...